package com.iw.core.security;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.DefaultRedirectStrategy;
import org.springframework.security.web.RedirectStrategy;
import org.springframework.security.web.WebAttributes;
import org.springframework.security.web.authentication.AuthenticationFailureHandler;
import org.springframework.security.web.util.UrlUtils;
import org.springframework.util.Assert;

public class LoginAuthenticationFailureHandler implements AuthenticationFailureHandler {

	protected final Log logger = LogFactory.getLog(getClass());

	private String defaultFailureUrl;
	private boolean forwardToDestination = false;
	private boolean allowSessionCreation = true;
	private RedirectStrategy redirectStrategy = new DefaultRedirectStrategy();

	public LoginAuthenticationFailureHandler() {
	}

	public LoginAuthenticationFailureHandler(String defaultFailureUrl) {
		setDefaultFailureUrl(defaultFailureUrl);
	}

	/**
	 * Performs the redirect or forward to the {@code defaultFailureUrl} if set, otherwise returns a 401 error code.
	 * <p>
	 * If redirecting or forwarding, {@code saveException} will be called to cache the exception for use in the target view.
	 */
	public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException exception) throws IOException, ServletException {
		System.out.println("登陆失败!");
		if (defaultFailureUrl == null) {
			logger.debug("No failure URL set, sending 401 Unauthorized error");

			response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Authentication Failed: " + exception.getMessage());
		} else {
			saveException(request, exception);

			if (forwardToDestination) {
				logger.debug("Forwarding to " + defaultFailureUrl);

				request.getRequestDispatcher(defaultFailureUrl).forward(request, response);
			} else {
				logger.debug("Redirecting to " + defaultFailureUrl);
				redirectStrategy.sendRedirect(request, response, defaultFailureUrl);
			}
		}
	}

	/**
	 * Caches the {@code AuthenticationException} for use in view rendering.
	 * <p>
	 * If {@code forwardToDestination} is set to true, request scope will be used, otherwise it will attempt to store the exception in the session. If there is no session and
	 * {@code allowSessionCreation} is {@code true} a session will be created. Otherwise the exception will not be stored.
	 */
	protected final void saveException(HttpServletRequest request, AuthenticationException exception) {
		if (forwardToDestination) {
			request.setAttribute(WebAttributes.AUTHENTICATION_EXCEPTION, exception);
		} else {
			HttpSession session = request.getSession(false);

			if (session != null || allowSessionCreation) {
                String msg = exception.getMessage();
                if(msg.equals("Bad credentials")) {
                    msg = "密码错误！";
                }
				request.getSession().setAttribute(WebAttributes.AUTHENTICATION_EXCEPTION, msg);
			}
		}
	}

	/**
	 * The URL which will be used as the failure destination.
	 * 
	 * @param defaultFailureUrl
	 *            the failure URL, for example "/loginFailed.jsp".
	 */
	public void setDefaultFailureUrl(String defaultFailureUrl) {
		Assert.isTrue(UrlUtils.isValidRedirectUrl(defaultFailureUrl), "'" + defaultFailureUrl + "' is not a valid redirect URL");
		this.defaultFailureUrl = defaultFailureUrl;
	}

	protected boolean isUseForward() {
		return forwardToDestination;
	}

	/**
	 * If set to <tt>true</tt>, performs a forward to the failure destination URL instead of a redirect. Defaults to <tt>false</tt>.
	 */
	public void setUseForward(boolean forwardToDestination) {
		this.forwardToDestination = forwardToDestination;
	}

	/**
	 * Allows overriding of the behaviour when redirecting to a target URL.
	 */
	public void setRedirectStrategy(RedirectStrategy redirectStrategy) {
		this.redirectStrategy = redirectStrategy;
	}

	protected RedirectStrategy getRedirectStrategy() {
		return redirectStrategy;
	}

	protected boolean isAllowSessionCreation() {
		return allowSessionCreation;
	}

	public void setAllowSessionCreation(boolean allowSessionCreation) {
		this.allowSessionCreation = allowSessionCreation;
	}

}
